My PC shut down today while I was playing some games, and when I tried to turn it on, it booted, almost got to windows, and shut down. I tried twice, and then I gave up. I unplugged it, opened it up and saw a lot of dust on the fans and heat sink. I don't have a compressed air can, so I just blew into it (and inhaled a lot of dust), and just brushed off most of the dust. I booted it up, and it worked fine. I suspected overheating, so I checked the CPU temp on CPUID HWMonitor, and it's around 50-60C, sometimes over 60C. I've got an AMD FX-6300, and I just use the heatsink and fan that came with it. My case is a Thermaltake Chaser A31 with the default fans, if that matters. I'm planning on buying a can of compressed air, and cleaning it properly soon, and testing it out if it turns out that the temp is too high.